Fig. 4.

Production of geraniol in ERG20 promoter replacement strains. a Transcription level of ERG20 controlled by different promoters. b Production of geraniol in engineered strains in batch fermentation. c Cell growth of engineered strains in batch fermentation. d Geraniol production in YZG13-GE1 and HXT1 promoter replacement strain (YZG19) in fed-batch fermentation. All strains were grown in SD medium with 2% glucose, and the cells were collected when OD₆₀₀ reached 0.6 to extract mRNA for ERG20 mRNA and transcription determination. Aerobic fed-batch fermentations were carried out by feeding a 50 g/L glucose and 350 g/L ethanol (1:7) mixture at 0.1/h feed rate. The data shown are representative of duplicate experiments, and the error bars represent the standard deviation